Tuesday, January 25, 2011

Mechanical friends.

Mechanical friends? Really? Yes.
Let me just dispense with the obvious. The Rabbit, the Thumper or whatever other motorized instrument of self pleasure may have come to mind by the title of this post...that ain't what I'm talking about! (this time)
Let's start with my favorite, the bicycle. The most efficient machine in man's history. The bicycle can move a fit person sixty miles in an afternoon with only a modicum of effort. If I had the time to spend, I could ride 60 miles every day and the biggest consequence would be great looking buns. This is within reach of most fit people. A leisurely pace on a bike can move you 60 miles in about 4 hours. Piece of cake!
There's also the unicycle. Not as efficient, but a lot of fun. Pedicabs and Surreys are on the list too, but none are as efficient at the bike.
We all love our cars and motorcycles, but let's not forget all the other transportation machines we've become friendly with. Boats, planes, jets & rockets. Track vehicles like snow mobiles and even simple machines like a hang glider or hot air balloon. We love to move around and machines make it faster, more fun and easier. What could be friendlier than that?
Fork lifts, conveyor belts, elevators and cranes have been with us for many years. These machines have allowed us to build bigger and bigger structures for many purposes. Then there's the technology that lets us put them all together. Nuts, bolts and welders.
The magic blender! Make those margaritas! Hand mixers, crock pots, toaster ovens, food processors and even your stove and microwave are all machines. Where we be without them? These things not only help us prepare our food, they have also been instrumental in the development of all the medicines and chemicals we use every day. Cooking is really nothing but simple chemistry and the machines that help us have advanced our society in ways we cannot fully comprehend.

You guys know about all these things and what they do, let me try to give you a better handle on how they work.
Those of you, who know me well, know that I understand machines really well. Some people have asked me how. Here it is in a way that I hope will lend itself to your own understanding of machines.
All mechanical devices, no matter how complicated they may seem, can be broken down to their most basic elements. These basic elements are always one or more of four basic machines.
The lever
The most basic machine there is, is the lever. A lever multiplies force, but it can’t do it all alone. The lever has to work with something else. It needs something to pry against to work.
The fulcrum
This is what the lever works against. A pivot point. The way it works is really simple too.
Let’s say you want to lift a car that weighs 2000 pounds. Place an eleven foot lever under the car. One foot away from the car, place your fulcrum. This leaves ten feet of lever on the other side of the fulcrum. Notice the ratio of 10:1? Because of this ratio we get a conversion of force. Namely, 200 pounds of downward force on the long side of the fulcrum will equal 2000 pounds of upward force on the short side, Ten times the length of the lever equals ten times the force. Also, five feet of downward movement on the long side translates into only six inches of upward movement on the short side. This is the trade off. Force multiplies while motion divides.

The inclined plane
Then comes the inclined plane. The simple ramp. This is another way to multiply effort. You can’t push a 1000 pound weight straight up for one foot. That would take 1000 pounds of force. You could generate that much force with a lever, but the balance could be precarious. If you build a ramp that is ten feet long, pushing the weight would only take 100 pounds of force. Ten times the distance equals one tenth the force.
The telescopic extension
This is a little bit of a stretch because the telescopic extension doesn’t really change the amount of effort that can be performed. Still, it is so common that it warrants mention.

That’s it! ALL machines fall into these four categories!
Really? All machines? That’s right, all machines operate on these simple principles.
Wait! What about the wheel? The wheel is a lever. The axle of a wheel is the fulcrum. What about gears, pulleys, winches and cranes? All, more levers.
Wait! What about a screw? The screw is an inclined plane wrapped around a rod.
Once you can break a machine down to its lowest common denominator, it becomes very easy to understand. Machines are our friends and it's good to understand your friends.

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